Alright, let me translate: Have you've reached a decisive conclusion after a careful analysis of the detailed study of the LED lighting system I am currently using? In other words, what do your numbers tell you, or better yet, what do they tell me? In other words, put it inEnglish!

No definite conclusions yet. The problem is that Iâm not too sure about the results. I donât have detailed info about low power LEDs, except that they dissipate about 70mW each, but that should be at 20mA (not 25). I could not jippo the program enough to get around that. So the immediate conclusion is that the results are only 25% accurate.In other words:Light output (PAR): ranges from 39 to 65 PARLight output (Lumen): ranges from 3000 to 5000 Lumen

Maybe that doesnât worry you too much, but it worries me, coz LEDs are extremely non-linear, which may cause you to draw the wrong conclusion.

One point based on these result is that there is a lot of red light. Five bands of spectra, 50% of which is red (3000K)! In my opinion, three bands (30% red) is more than enough for plants. As a result, the Red/Blue ratio is lopsided at a level of 2(?) (sunlight = 0.92). So it looks as if the manufacturer has put more effort into the color rendering than into plant growth.

But this is where I could be wrong, so . . . My initial recommendation is to carefully watch your plants and algae.

J.B. wrote:I suppose it was kinda silly of me to expect to see any pics of the tank with these new lights.

Remember - phantom tank, JB - ScottFish is really an alien trying to seduce us to his spaceship!

So while we wait (and wait) for Dutch to do all his calculations, what is the empirical data from your phantom tank suggesting, ScottFish? Are your plants growing under these new-fangled lights or fading away into brown puddles of mush?

The results certainly look a lot more credible after I introduced some âgenericâ LEDs that represent the real thing more closely.The LEDs now operate at 20mA and 70mW power - as expected - so I am a lot more confident about these results.

At 95Lm/Watt, this would boil down to: â 6W/ftÂ˛, which translates to âlowâ light intensity (see: [utp=http://users.iafrica.com/c/co/cordewit/aquarium/light_levels_all.xls]Light Levels All[/utp])However, 8 PAR/ftÂ˛ represents a more âmediumâ intensity level. The discrepancy is caused by the fact that âLumenâ refers only to the visible part of the spectrum centred on 555nm, while PAR represents the full spectrum from 400 â 700 nm.(Obviously, there is more light projected than we can see.)

All I can recommend is to install the unit as low as possible above the water surface (if you can) in order to avoid losing light that may otherwise spill over.

Dutchman, thank you for doing the calculations. I find all this utterly fascinating. When I first started in this hobby as a young teen, my grandfather and I didn't know jack squat about aquarium lighting. (He got me into the hobby.) This was back in the mid 1970s. The amusingly ironic part is that my grandfather was co-owner/co-founder of a lighting company. He made lighting fixtures for a living. But it was so difficult back then for us to find out much information at all about various aspects of tropical fish keeping, especially in regards to aquatic plants and lighting. No doubt if he were alive today my grandfather would be all over this forum.

I have been interested in LED lighting, but figured that it would only work for low light plants. What intrigues me is that Aqua Design Amano now sells LED lighting. My thought was surely Takashi Amano wouldn't give his stamp of approval to an LED lighting system if you couldn't use it to grow plants.

Of course I'm making this up. Who else can think of a such aload of numerical crap?

@Andrew:Very touching story. I like it.Yes, LEDs are the future, but - because of their characteristics - it will (initially) be difficult for people to understand how they work. They last a long time - at least 10 years above a tank - but they are still expensive, which requires you to make the right choices now.At this point in time, DIY is not a bad choice. You can aleady build nice units with the parts that are available, so you can save some money and learn at the same time.